Combination light fixture and ventilating unit



1958 v L. w. BURNS 2,845,855

COMBINATION LIGHT FIXTURE AND. VENTILATING UNIT Filed Nov. 14. 1956 2 Sheets-Sheet 1 22b 22 P 222 2 46 4o 6 A I2 62 so 22d 22 38b 66 4a 3a 8 .nl '06 488 I d 5 O6 5 *1 76 VII; 8

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LESTER W. BURNS TTO RN EYS 5, 1958 L. w. BURNS 2,845,855

COMBINATION LIGHT FIXTURE AND VENTILATING UNIT Filed Nov. 14. 1956 2 Sheets-Sheet 2 22c 44 ,22a 60 A 65 64 22a 6 v i I 45 46 I, A? .:i W "221mb ..1l

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OF AMBIENT $7M, ATTORNEYS United States atent ()fiice COMBINATION LIGHT FIXTURE AND VENTILATING UNIT Lester W. Burns, Itasca, Ill., assignor to The Pyle-National Company, Chicago, 111., a corporation of New Jersey Application November 14, 1956, Serial No. 622,157

4 Claims. (Cl. 98-40) This invention relates generally to ventilating and illumination apparatus and more particularly to a combined 1 the surface of the distributing unit into the same space.

It is an object of the present invention to provide a combination air and light distributor unit of the type described wherein an improved and more uniform circulation of air is achieved.

Another object of the invention is to provide an improved ventilating apparatus of the type described wherein an improved air circulation means is present which will cause the light source to operate at an optimum temperature for maximum light emission and longer operating life.

An object of the invention is to provide a combined lighting and ventilating fixture with improved structural and functional characteristics.

Other objects and advantages will become more apparent with the disclosure of the invention in the description of the preferred embodiment thereof as found in the specification, drawings and claims, in which:

Figure 1 is a perspective view showing certain of the elements in exploded relationship and illustrating details of construction of the combined ventilating and lighting unit;

Figure 2 is a vertical sectional view taken through the combined lighting and ventilating fixture;

Figure 3 is a vertical sectional view taken along line III-III of Figure 2;

Figure 4 is a vertical sectional view similar to Figure 3 but illustrating a slightly modified form of fixture; and

-output against its operating temperature.

Although the principles of the present invention are of general utility, the subject matter finds a particularly useful application in architectural installations of so- ,called suspended ceilings or suspended acoustical ceilings wherein a Wall or a ceiling is spaced inwardly from a structural wall or ceiling of a building. Thus, the inner wall forms a part of the finished surface exposed to the interior of the space being ventilated. In ceiling constructions of that type, the so-called primary ventilating ducts and electrical wiring conduits are frequently extended into and through the space behind the inner wall or ceiling, thereby concealing the same from the interior of the room being ventilated.

By spacing air diffuser units throughout the extent of the inner wall and by connecting the air diffuser units to the primary ventilating air ducts, a supply of ventilating air may be diffused throughout the space being ventilated.

It will be understood, however, that capacity limitations and space limitations frequently result-because it is not only necessary to adequately ventilate the space but light- 0a! ing must also be provided. In some installations the lighting units may occupy so much room that an adequate capacity of air diffuser units cannot be installed, or vice versa. According to the principles of the present invention, all of such difficulties are obviated by combining the light fixtures and the air diffuser units. In that manner architectural limitations are minimized Without sacrificing ventilating efficiency or light efficiency. Moreover, be cause of the specific improvements incorporated'into the combination unit of the present invention, the flow of ventilating air through the air diffuser unit does not deleteriously affect the performance efficiency of the lighting fixture. In this connection, it may be noted that the performance efficiency of fluorescent bulbs, for example,

appears to be directly proportional to the environmental temperatures. The present invention accomplishes an efiicient combination wherein certain structural components develop dual functions from a standpoint of air diffusion as well as from a standpoint of illumination distribution.

In a typical architectural structure, a plurality of run ners such as 8 and 10 are extended across the room from which an inner wall or false ceiling is suspended. Similar spaced lateral runners 12 may be connected thereto. It will be understood that the runners form a framework which is connected in firm assembly with the structural wall of an architectural building and provide the means of support to suspend the inner wall or ceiling 20 therefrom.

Extending into the space behind the inner wall or ceiling is a ventilating duct shown in Figure 1 at 46. In Figures 2-4, the inner Wall is indicated at 20 and it will be noted that the inner Wall 20 is provided with a selected plurality of openings 29a, which, according to conventional practice, would be adapted to receive either a lighting fixture or an air diffuser unit. r

In accordance with the principles of the present invention, each of the openings 20a in the inner wall or ceiling 20 receives a combined air diffuser and light fixture of the present invention, as shown at 6.

The combined unit of the present invention advantageously embodies the features of a so-called trolfer-type light fixture and an air diffuser unit operable on the so-called pressure displacement type principle. Thus, there is provided a shell indicated generally at 22 and including a generally horizontally disposed top wall 220: with depending side walls 22b spaced apart from one another and extending an appreciable distance in parallel relation to one another. The parallel portions 221: terminate in oppositely outwardly curved portions'indicated at 24 and 26, respectively. At the end of each curved portion 24 and 26, there is an offset flange portion 25 including a horizontally disposed leg 25a and a depending vertical leg 25b. Means are provided as a flange or escutcheon shown generally at 18 to mount the combined unit 6 in flush relationship with the inner wall or ceiling 20. The exemplary illustrative application of the present invention is a flush mounting for an acoustical-type ceiling, although it will be appreciated that the combined air diffuser and lighting unit could be incorporated in'other specific forms of installations.

The top wall 22a of the shell 22 has an opening 22c formed therein, which opening receives a collar mem ber 22d flanged as at 22a to overlie the edges of the opening 220.

The duct 46 is provided with as many outlet openings as there are air diffuser units and in the exemplary dis closure there is shown an air outlet 46a to which is connected a flexible tube or duct 44. The other end of the flexible tube or duct 44 is passed through the collar 22d into the interior of the shell 22, thereby to supply ventilating air at increased pressure to the combined diffuser unit and light fixture 6.

A transverse wall 68 extends across the interior of the shell 22 between the parallel wall portions 22b, 22b and partitions the interior of the shell 22 into an upper space indicated at A and a lower space indicated at B. The transverse wall 68 is preferably located to form an extension of the curved surfaces provided by the oppositely curved wall portions indicated at 24 and 26, thereby providing a continuous surface extending over the entire top of the space B. Such surface is indicated generally by S and is provided with suitable coating, if desired, to enhance the light-reflective properties thereof.

The shell 22 is provided with end walls indicated at 74 and 76. Attached to the end walls 74 and 76 in the lower space B are electrical sockets indicated at 90 and 92. Preferably, the sockets 90 and 92 are of the type adapted to energize fluorescent lamps and it will be understood that any selected plurality of sockets and corresponding lamps may be provided, there being two sockets 90 and 92 shown in Figure 3 for accommodating corresponding fluorescent bulbs indicated at 89 and 82 and there being three sockets indicated in Figure 4 at 95, corresponding pairs of oppositely disposed sockets 95 accommodating the fluorescent bulbs indicated at 84, 86 and 88. As shown in Figure 2, the fluorescent bulbs extend throughout the length of the lower space E. The rays of light emanating therefrom are directed outwardly of the space B through the bottom thereof and any rays impinging against the reflective surfaces S will likewise be reflected through the opening at. the bottom of the space B into the room.

Fluorescent lamps are primarily low pressure vapor lamps which make use of the ultraviolet energy from the mercury-arc discharged to activate phosphors coated on the inside bulb surface. Inside coating is essential because the glass bulb does not transmit ultraviolet radiations. Phosphors are selected which respond to radiations which are efficiently produced by the low-pressure, mercury-arc discharge. These lamps are hot-cathode types, a current being passed through both electrodes before they are subjected to the are potential.

According to the present invention, suitable starting and ballast means (not shown) are connected to the shell 22 and are preferably located in the upper space A.

It has been determined that the illumination efficiency of fluorescent bulbs is in a l rge measure dependent upon the maintenance of a suitable operating environment. In this connection, reference may be advantageously made to the graph shown in Figure 5 which illustrates the performance characteristics of a fluorescent bulb at different ambient temperatures. It will be noted that at low temperatures ranging from O to F., a fluorescent bulb enjoys a relative output percentage of less than 50. In like manner, in temperatures of in excess of 90, the relative output percentage decreases markedly.

It will be apparent to those versed in the art, therefore, that the combination of fluorescent lamps in an air diffuser unit presents a serious problem in that the flow of temperature-conditioned cooling air over a fluorescent bulb is likely to produce flickering and the bulb is likely to become severely discolored, thereby materially reducing the illumination efliciency thereof. Starting may also be diflicult. In like manner, temperatureconditioned heated air will deleteriously affect the operating performance of the fluorescent bulbs.

In accordance with the principles of the present invention, the reflective surfaces S are provided with means forming an air-diffusing outlet through which a supply of ventilating air is diffused through the lower space B and into the space being illuminated and ventilated. Special provision is made, however, to form the air diffusion means with a directionl sense whereby the flow of ventilating fluid is directed away from and past the fluorescent bulbs, thereby to diffuse the ventilating air through the l lower space E without seriously interfering with the ambient environment of the fluorescent bulbs.

More specifically, the transverse wall 68 is provided with laterally spaced longitudinal rows of elongated slots including a first row of slots 1% and a second row of slots 102.

The slots and 162 are preferably formed by striking out offset portions forming angularly inclined baflle walls 194 and 106, respectively, inclined at an angle relative to the plane of the transverse wall 68 so that the ventilating air passing through the slots 100 and 102 will be directed away from the fluorescent bulbs 80 and 82, or from the fluorescent bulbs 84, 86 and 83.

Each of the angularly inclined baffle walls 104 and 196 terminate in a lip and it will be noted that end walls 135a at opposite ends of each respective slot ltltl and 102 insure that all of the air baffled and directed through the corresponding slots will flow in a preferred direction away from the adjoining fluorescent bulbs.

In order to provide a regulated supply of ventilating air at increased pressure to the rows of slots 100 and 102, supplemental structural components are incorporated into the shell 22. Thus, there is provided a cover member 38 which includes an upper wall portion 38a and depending side walls 381; which engage against the transverse wall 68 as at 380. There is thus provided within the upper space A, a plenum space P which overlies the longitudinal rows of slots 100 and 102.

A central opening 38d is formed in register with the opening 220 and an upstanding collar 48 flanged as at 48a to overlie the edges of the openings 38d is assembled to the upper wall 33a in the opening 38d. The end of the flexible tube or conduit 44 is connected to the collar 48 and a bracket assembly 62 is also connected to the collar to support the stem 60 of an adjustable valve assembly indicated generally at 58 including a generally comically-shaped valve head perforated as at 66 and adjustable in the direction of the stem 60 to meter and regulate the flow of air from the flexible tube or conduit 44 into the plenum space P.

As described above, the flanges 25 are disposed on opposite sides of the bottom opening of the troffer shell, through which opening the air and light rays are diffused. To enhance the decorative appearance of the combined diffuser unit and lighting fixture, several different forms of structure may be employed. For example, in the form of the invention illustrated in Figures 2 and 3 a Waffle or egg crate type grill is indicated at 91. The grill 91 includes a plurality of separated strips of metal, plastic or other strip material disposed vertically and extending longitudinally of the fixture as shown at 93. The strips 93 are crossed by and connected to separated vertical strips 94 disposed in lateral direction. As shown in Figures 2 and 3, the grill 91 extends across the opening and is received in the notches provided by the flanges 25, 25 for support on the flanges provided by the mounting or support means 18. The entire grill 91 may be removably mounted and, if desired, may be supported by appropriate hinges to afford easy access in relamping the fixture.

In the embodiment of Figure 4 an imperforate translucent sheet member 96 is provided in the bottom opening of the shell 22. The sheet member 96 may take the form of a diffusion-type glass or plastic. To support the sheet member 96, there is provided a frame indicated generally at 98 and including a channel portion 98a providing upper and lower spaced apart legs receiving therebetween the edges of the sheet member 96. The frame 98 further includes a side strip portion indicated at 98b, the strip portions 98b at opposite sides of the fixture being formed with longitudinal rows of elongated slots 108 and 119, respectively. The slots 108 and are generally similar in construction and disposition to the slots 102 and 106 in that portions of the strip material are struck out and offset, thereby to provide slotted passageways which direct air from the space B into the space being ventilated.

By virtue of the arrangement described above, the combined air diffuser unit and light fixture aflfords the distribution of ventilating air through the reflective surface of the light fixture, thereby affording a unit which will, in the confines of a single ceiling opening, diffuse ventilating air and emit rays of light. Moreover, even though the ventilating air is passed directly through the light-reflective surfaces of the unit, the flow of air is so bafiied and directed that the fluorescent bulbs are permitted to operate in an ambient which closely approximates the normal room ambient so that the bulbs will maintain an output efiiciency corresponding to the optimum operating range of the bulbs.

It will be understood that the unit herein disclosed can be used as an air return as well as an air distributor, thereby further enhancing the advantages and utility thereof in a ventilating system apparatus.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of'my contribution to the art.

I claim as my invention:

1. In combination with a ceiling of a space to be illuminated and ventilated, a false ceiling spaced below said ceiling, a supply duct extending into the space above said false ceiling, a combination lighting-ventilating unit in said false ceiling and comprising a troffer light housing having side wall portions connected to the edges of an opening in said false ceiling and having other Wall portions extending upwardly and inwardly form a lighting trough above the level of the false ceiling, elongated fluorescent tubes in said lighting trough, said other wall portions having a light-reflective surface formed on one side thereof behind said tubes, a plurality of air-diffusion passages extending through said inwardly extending portion of said other Wall portions and intersecting said refiective surfaces, said trofier housing including additional means above said lighting trough forming with said inwardly extending portion a plenum chamber behind said air difiusion passages, and a flexible conduit interconnecting said troflfer light housing at said plenum chamber and said supply duct to supply ventilating air, said air diifusion passages having baffied edge portions directing air flowing through said passages towards the sides of the light trough and away from said fluorescent tubes, thereby to maintain the ambient of said tubes within optimum operating range, whereby ventilating air is diffused and light rays are emitted and reflected simultaneously through said false ceiling via the lighting trough of the trofier light housing and into the space being illuminated and ventilated.

2. In the combination of claim 1, said horizontal portion of said light troffer housing having at least one longitudinal row of slots formed therein to provide said air diffusion passages, each of said slots having struck out edge portions inclined away from the horizontal to form the baflied edges directing air flowing through said slots away from said fluorescent tubes.

3. In the combination of claim 1, an egg crate light diffuser grill carried by said light troifer housing and extending across the bottom of the lighting trough at the level of said false ceiling.

4. In the combination of claim 1, a cover carried by said light troifer housing and extending across the bottom of the lighting trough at the level of said false ceiling, said cover comprising a peripheral frame having a plurality of slotted openings formed therein and extending therethrough for the passage of air outwardly from said lighting trough, and a translucent center portion carried by said peripheral frame through which light rays are emitted into the space.

References Cited in the file of this patent UNITED STATES PATENTS 2,010,322 Riddell Aug. 6, 1935 2,190,937 Demuth Feb. 20, 1940 2,310,414 Fritzam et al. Feb. 9, 1943 2,359,021 Campbell et a1 Sept. 26, 1944 2,564,334 Kennedy Aug. 14, 1951 OTHER REFERENCES 760,850 Great Britain Nov. 7, 1956 

